I did this puzzle and came up with a problem. In row 1, columns 3 and 4 I have a 2/6 pair in each space and likewise in row 9, columns 3 and 4 I have a 2/6 pair in each space. Can someone tell me what I did wrong or should I start over again. Thanks!

Just in case you were concerned that these four cells formed a “deadly pattern,” they do not. Such a pattern arises if the four cells at the corners of the rectangle occupy two boxes, here they are spread over three.